This study was a three- arm, parallel-group, placebo-controlled clinical trial to compare the effects of amitriptyline, mexiletine and placebo on HIV-related peripheral neuropathy. Although amitriptyline and mexiletine are commonly used in clinical practice, there are no published reports of the safety or efficacy of these agents in HIV-related peripheral neuropathy. Participants were randomly assigned to receive one of the following regimes: amitriptyline, started at 25 mg nightly, then titrated upward to a maximum of 100 mg nightly, over a period of up to four weeks. Patients were to remain on the final dose of medication for at least four weeks. Mexilletine, started at 150 mg at night and titrated upward to a maximum of 300 mg bid, over a period of up to four weeks. Patients were to remain on that dose of medication for at least four weeks, or placebo, benztropine was used as an active placebo to match amitriptyline.